JP3436426B2 - Steam cleaning method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam cleaning method for cleaning using a solvent. 2. Description of the Related Art As a method of cleaning using a solvent, a cleaning apparatus having an opening in an open state is generally used for taking in and out an object to be cleaned in terms of work efficiency. When the object to be cleaned is taken in and out of the cleaning apparatus, it is difficult to avoid deterioration of the working environment due to leakage of the solvent or loss of the solvent accompanying the object to be cleaned. Because of this, leakage of the solvent is inevitable, and the types of solvents that can be used are limited due to the toxicity and flammability of the solvent. Recently, chlorinated hydrocarbons and fluorinated hydrocarbons have been used. I have. [0003] However, these solvents are said to cause the ozone depletion of the earth, and their use has been restricted, and reduction in loss and conversion to other solvents are required. On the other hand, as a method for solving the problem, a method of sealing the entire system is proposed in Japanese Patent Application Laid-Open No. 3-22981. [0004] Most of the problems have been solved by the method described in Japanese Patent Application Laid-Open No. Hei 3-22981. When washing the cleaning object with steam, it is necessary to pressurize the inside of the steam generator slightly to introduce the steam of the steam generator into the washer. It is inconvenient. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the temperature of an object to be cleaned in a closed cleaning device is determined by the condensation of cleaning steam. Temperature (dew point)
At a lower temperature, the steam from the steam generator is guided to the washer in the steam cleaning performed by contacting the cleaning steam with the object to be cleaned exposed, and condensed residual gas from the steam cleaning is removed. The present invention also provides a steam cleaning method characterized by circulating from a cleaning device to a steam generator, bringing the cleaning solution into contact with a solvent liquid in the steam generator, and circulating again with the vaporized steam to the cleaning device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of the present invention will be described below with reference to FIG. This is only an example of the embodiment, and other specific methods can be adopted. [0007] The internal temperature of the steam generator 8 is at least higher than the temperature of the object to be cleaned, and is heated by the heater 9 at a temperature not higher than the boiling point of the solvent so that the temperature difference with the object to be cleaned required for cleaning. Adjusted. The bottom of the cleaning device 1 and the positions of the valves 13 and 16 are installed so as to be always higher than the solvent liquid level of the solvent tank 4. The liquid solvent 5 in the solvent tank 4 is adjusted in the cooler 7 at a temperature lower than the condensation temperature (dew point) of the cleaning steam and in consideration of a temperature difference required for cleaning. [0008] An object 3 to be cleaned is set in the cleaning device 1, and is closed by the cleaning device lid 2. Then, pump 6, valve 1
After the liquid solvent 5 is introduced into the cleaning device via 5 and the object to be cleaned is immersed, the liquid solvent is circulated to the solvent tank 4 via the valve 13. After the cleaning is completed, the valve 15 is closed and the valve 16 is opened to draw out the liquid solvent into the solvent tank 4. Next, the valve 14 is opened, and the steam from the steam generator 8 is introduced into the cleaning device 1 by the fan 12. The vapor is condensed and liquefied on the surface of the object to be cleaned and cleans the object to be cleaned. The condensed liquid solvent is returned to the solvent tank 4 via the valve 16. The condensed residual gas is introduced into the evaporating solvent solution 11 of the steam generator via the valve 17 and the gas disperser 10, and is circulated again to the cleaning device 1 with the generated steam solvent. The condensed residual gas introduced into the steam generator 8 is:
It is introduced in a state of being dispersed in the liquid. The liquid solvent of the steam generator 8 is supplied from the pipe 18 through the liquid solvent supply valve 21 to an amount corresponding to evaporation. When the temperature of the object to be cleaned reaches a predetermined temperature rise, the steam cleaning ends. Normally, changes in gas volume in the system due to changes in temperature and vapor pressure during the cleaning operation are equalized with the atmosphere by the gas recovery device 19 and the closed system pressure release pipe 20. An embodiment based on FIG. 1 will be described below. As the solvent, 1.1.2. Trichlorotrifluoroethane was used. 25 kg of an object to be washed is set in a washing machine 1 having a diameter of 40 cm and a depth of 35 cm,
After washing with a liquid solvent of 10 ° C., steam from a steam generator 8 temperature-controlled to 43 ° C. is introduced into the washing machine with a fan at a speed of about 20 cubic meters / hour for 3 minutes, and the condensed residual gas is steamed. Circulated to generator 8. The pressure in the steam generator may be slightly lower than the pressure in the scrubber, and does not need to be particularly high as in the prior art. The condensation temperature of the vapor was 43 ° C. The temperature of the steam generator could also be adjusted arbitrarily. When there was no circulation of condensed residual gas from the washer to the steam generator, the temperature of the steam generator needed to be higher than the boiling point. As described above, according to the steam cleaning method of the present invention, the condensation temperature of the cleaning steam can be arbitrarily selected by the temperature of the steam generator. Also, the amount of steam for cleaning is
It is possible to adjust the steam feed amount, for example, the fan feed amount, which is safe and convenient.

[Brief description of the drawings] FIG. 1 shows a flow sheet according to an embodiment of the present invention. [Explanation of symbols] 1: Washer 2: Washer lid 3: Object to be cleaned 4: Liquid solvent tank 5: Liquid solvent 6: Liquid solvent pump 7: Cooler 8: Steam generator 9: heater 10: Gas disperser 11: Solvent liquid for evaporation 12: Fan 13: Valve 14: Valve 15: Valve 16: Valve 17: Valve 18: Pipe 19: Gas recovery device 20: Pipe for closed system pressure release 21: Liquid solvent supply valve

Claims (1)

(57) [Claims] [Claim 1] The temperature of an object to be cleaned in a closed cleaning device is:
In steam cleaning performed at a temperature lower than the condensation temperature (dew point) of the cleaning steam while exposing the object to be cleaned to the cleaning steam, the steam from the steam generator is guided to the cleaning device, and the steam cleaning is performed. Steam cleaning method comprising circulating condensed residual gas from the cleaning device to the steam generator, bringing the condensed gas into contact with the solvent liquid in the steam generator, and circulating the condensed gas again with the evaporated steam to the cleaning device.